CCs for the data sets shown in Fig 2.

Uncorrelated data (A) and slightly noisy data following a clear nonmonotonic relationship (B) show poor CCs in all cases. A nonlinear but monotonic relationship (C) is captured by the Spearman CC but yields low Pearson CC. A linear relationship is characterized by high Pearson CC (D, E), but only a good agreement between the two data series (E) yields a high concordance CC.